This invention relates to typewriters, and particularly to a novel device for use with typewriters to create bold face typing.
It is desirable to be able to create type of bold face appearance with a typewriter and efforts have been made to do so in older manual-operated typewriters. For example, U.S. Pat. No. 2,544,998 to Kissell describes a mechanism for partial displacement of the typewriter carriage and printing surface in both a horizontal and vertical direction so as to permit relative displacement of the typed letters on a sheet to create bold face characters. U.S. Pat. Nos. 597,038 (Turner) and 1,950,761 (Thompson) described mechanisms for carriage displacement so as to effect a variation in normal typed-character placement, in particular to create superimposed characters or "shaded" characters. Furthermore, U.S. Pat. No. 3,270,851 (Goldsmith) describes a novel half-space mechanism by which a typist can correct errors and justify margins more easily by half-space displacement of the carriage.
None of these patents, however, describes a simple, inexpensive and effective means for providing bold-face typing in modern electric typewriters having manual half-space mechanisms and removable and interchangeable typing elements, such as the IBM "Selectric" series of typewriters.